Plastic varieties simple identification methods

Plastic varieties simple identification methods

发布时间：2014-12-12

Plastics can be used to identify the scientific method of infrared spectroscopy, electron paramagnetic resonance and X-ray apparatus, etc., but you can also use a more simple method of identification. The following brief summary identification methods:Sensory evaluationSensory evaluation (organizing students to participate in the identification of plastics)(A) SeeLook at the product color, transparency.Transparent products are: polystyrene and plexiglass.Translucent products are: low-density polyethylene, cellulosics, polyvinyl chloride, polypropylene, epoxy resin, unsaturated resin.Opaque products are: high-density polyethylene, polyurethane, and a variety of colored plastic.(B) listenWhen struck by hard objects, the sound is different, like polystyrene metal sound, the sound of thick plexiglass, nausea.(C) touchTouch feels like waxy product, must be polyolefin material. Secondly, the mode of its soft and hard, can be simply expressed as follows:→ soft hardPolypropylene, polystyrene → → → polyamide plexiglass → high density polyethylene LDPE → → → hard PVC soft PVCThen test the surface hardness, pencil hardness with different surface, you can make a difference:Polyethylene plastic with HB pencil can draw a line mark;Polypropylene plastic pencil can draw a line with ZH marks.Due to differences in physiological conditions of people, does not feel the same sense the resulting identification, so this approach is for reference only.Several plastic discriminate on the basis of the Confusing(A) polyethylene and polypropylene plastic identification basisPolyethylene and polypropylene are milky white translucent plastic, light can float on water, burning phenomenon is basically the same. However, there are two significant differences: polyethylene wax hand touch creamy, soft texture can be bent, and polypropylene hand touch smooth and delicate, but no waxy creamy texture stiffer toughness; polyethylene plastic in significantly softened in boiling water, Polypropylene plastic softened in boiling water is not significant; polyethylene plastic strip-like stretch when the "narrow neck" to produce, and no polypropylene.Discriminate on the basis of (two) PVC and polyethylene plastic filmPVC and polyethylene processing methods: PVC with calendering pressed into monolithic film, polyethylene blown into the legal system to double tubular bag; see from the color and transparency: milky white translucent polyethylene, surface is shiny, waxy greasy hand touch feeling, multi-layer stack together continued to show a milky translucent rather than transparent PVC polyethylene high, bright yellow, with a multi-layer stack of yellow, smooth hand touch but there are sticky feeling, careful observation of fine lines have mold; different combustion phenomena: Polyethylene flammable, melt dripping with paraffin smell, and PVC flame retardant, flame green roots, and the pungent odor of hydrochloric acid release; polyethylene small proportion can float on water, and PVC sink in water.(C) phenol and urea-formaldehyde plastic identification basisBoth are thermosetting plastics, with hard and opaque features, mainly the following differences: usually dark brown Bakelite, urea-formaldehyde plastics, mostly light-colored, and bright color; Bakelite section loosely structured, and urea-formaldehyde plastic section compact structure; burning smell phenol phenol release, charring cracking phenomenon partial contact with the flame, urea has urea odor escaping white cracking phenomenon at the contact with the flame.(Four), polystyrene, polyvinyl chloride, polyethylene plastic identification basisDiscrimination on the basis of these three plastic has the following five areas:1. Color and transparencyPolystyrene plastic brightly colored, transparent as glass; PVC color and transparency worse than polystyrene; polyethylene plastic translucent appearance products such as wax and dye bleed easily.2. FeelPS feel smooth, hard surface, bump afraid, afraid of extrusion; PVC feel relatively smooth, thin-film products are sticky feeling; there are hard and soft products of the points; polyethylene creamy feel waxy , product flexibility to bend resistant.3. The relative densityThe relative density of polystyrene is l.05 ~ 0.06, slowly sinking in water; relative density PVC soft plastic is 1.24 to 1.45, the relative density of hard plastic 1.35 to 1.45, so quickly in water under Shen; high density polyethylene relative density of 0.94 to 0.97, the relative density of the low density of 0.91 to 0.93, it is floating in water.4. SoundWhen a hard object percussion, polystyrene has crisp metallic sound, loud but not brittle PVC, polyethylene stuffy and not brittle.5. FlammabilityPolystyrene flammable, the flame was orange, take floc smoke unpleasant pungent odor of styrene monomer; PVC can not spontaneous, from the fire extinguished, the flame yellow, green roots, hydrochloric acid odor release ; polyethylene flammable, flame is yellow, the roots of the blue, take a small amount of smoke and soften burning like a candle, tears dripping wax, paraffin odor release.